The present invention relates generally to solid state heat management, and more specifically to pulsed electrothermal ice protection systems.
Ice protection systems for aircraft include de-icing and anti-icing systems that remove and prevent ice buildup, respectively. Many ice protection system rely on direct or continuous and/or intermittent resistive heating. Some newer systems use pulsed power heating with rapid discharge capacitors. Compared to traditional ice protection systems, pulsed power systems operate at higher peak temperatures, and are accordingly more power efficient, offering considerable energy savings. Pulsed power ice protection systems accumulate energy via capacitor banks that discharge briefly and rapidly into electrothermal elements (e.g. resistive heaters). Furthermore, heat pulses from pulsed power ice protection systems tend to remove ice in layers of chunks, thereby avoiding or reducing the ice run-back (i.e. melt water refreezing) common in traditional systems. Although traditional electrothermal melting systems are adequate to many applications, pulsed power ice protection systems offer improved power efficiency.
As mentioned above, pulsed power systems commonly use capacitors or capacitor banks to store energy for brief, high-intensity thermal pulses. Transient current flow through capacitor electrodes and collateral contact layers during capacitor discharge causes resistive heating due to bulk resistance. During capacitor discharge, high peak temperatures can cause permanent capacitance losses. Accordingly, capacitor self-heating during transient discharges can be a significant limiting factor in determining part lifetimes of capacitors and ice protection systems using capacitors.